The pedigree of TDE2 is shown in FIG. 1. In 1973, pollen from Encore mandarin (unpatented) was applied to stigmas of a tetraploid (Temple×4N Dancy) hybrid (unpatented) and the pollinated flowers were bagged to prevent insect pollination. Fruits were collected in winter 1974, seeds extracted from each fruit, and each seed was planted. The chromosome number of each seedling was determined and those identified as triploid seedlings were budded onto Troyer citrange rootstock. The resulting trees were planted in the field in Riverside, Calif. in 1976. These trees were evaluated for tree vigor, bearing, and seedlings, fruit flavor, fruit color, and other fruit quality traits from bearing until 1985. Five trees were selected from the original population and repropagated by budding onto C-32 citrange, C-35 citrange, Troyer citrange, and trifoliate orange rootstocks. One of these trees, now called TDE2, was selected and further asexually propagated. Two trees of the selection now called TDE2 were planted in the field in Riverside in 1987. When they began fruiting (approximately in 1990), these two trees were evaluated for the same tree and fruit quality traits as the original trees. In 1987, the selection now called TDE2 was chosen for additional testing because it combined medium or large fruit size, low seed number, rich fruit flavor, deep orange rind and flesh color, and acceptable peelability. Budwood of this selection was tested for viruses and other pathogens by the Citrus Clonal Protection Program and virus-free bud source trees were planted at Lindcove Research and Extension Center, Exeter, Calif. in 1991.
Using this virus-free budwood source, additional trees were propagated and planted at several California locations between 1993 and 1996. These included two locations in the Coachella Valley (Thermal, 73 trees, and the Coachella Valley Agricultural Research Station-CVARS, 4 trees), Ojai (12 trees) and Santa Paula (6 trees) in Ventura Co., and Valley Center (11 trees) in San Diego Co. These trial plantings provide most of the available data on TDE2. Several different rootstocks have been used in these evaluations, mostly Carrizo citrange, C35 citrange, and Schaub rough lemon. The trees in Valley Center are topworked Valencia orange on Troyer citrange rootstock. In general, no major effects of these rootstocks on fruit quality of TDE2 were observed, and no incompatibilities have been evident, but longevity of trees on various rootstocks is not known.